When automation turns bad

<dublin_core>
<dcvalue element="contributor" qualifier="none"
>Scanning, indexing, and description
sponsored by the Illinois State Library and
the University of Illinois at Urbana-Champaign
Library. Geo-referencing sponsored and
performed by the Geographic Modeling Systems
Laboratory, University of Illinois at
Urbana-Champaign.</dcvalue>
<dcvalue element="contributor"
qualifier="author"
>United States.
Agricultural Adjustment Agency.</dcvalue>
<dcvalue element="contributor"
qualifier="author"
>Aerial Photographs</dcvalue>

There appears to be an error here (“Aerial Photographs”
is apparently not the corporate or individual name of an author
of this photograph).

Can this be avoided?

How did this happen?

An obvious interpretation is that this is simple
tag abuse or human error, but the history of this description reveals
it to be an example of a more general and complicated problem. This is
the latest in a series of descriptions each derived from an earlier
version:

A paper description accompanied the original photograph, which had been taken in 1938.

In 1998 the photograph was scanned for inclusion in an image database made available on the web [grainger99]. A metadata record for the photograph was entered into a relational database. The fields for that database were derived from the FGDC [Federal Geographic Data Committee] Content Standard for Digital Geospatial Metadata [fgdc98].

In May of 2005 an OAI 2.0 metadata record was derived from that database entry, via a mapping from the database fields into Dublin Core.

Several months later the OAI record was transformed via XSLT [XSL Transformations] into a form suitable for ingestion into a DSpace installation.

When the record was exported from DSpace, additional DC [Dublin Core] metadata statements had been automatically added.

Verifying emulation, migration, normalization

How do you know when an emulator is working correctly?

How do you know when a migration program has produced a correct result?
How do you detect errors in migration?